带隔离型无损缓冲的三相单开关反激式整流器

A Three-Phase Single-Switch Fly-Back Rectifier with Lossless Isolated Snubber

提出了一种带无辅助开关隔离型无损缓冲的三相单开关反激式单级AC/DC的新型变换电路,它具有理论单位功率因数、准零电压关断、三相单开关、整体电路简单及调节性好等优点.附加的回能缓冲电路不需要额外增加检测或控制电路,并能减小开关管的开关损耗,提高电路的工作效率,而且还能有效抑制功率开关关断时由漏感储能引起的电压尖峰,扩大了开关管的安全工作区.分析了新型电路的工作机理,给出了关键参数的选择关系,并通过仿真和实验证明了该方案是可行并有效的.

A new three-phase flyback rectifier with loss recovery snubber is presented. A discontinuous current mode （DCM） operation with constant duty ratio allows achieving unity power factor. The principal characteristics are the very simple topology with only one switch, simple control scheme without input current feedback, and galvanic isolation between the input and output. By using a resonant energy recovery snubber, the switch can achieve zero voltage state （ZVS） at the turn off, and can also be protected against over-vohage caused by the leakage of transformers. Meanwhile, the switching loss is evidently reduced and the efficiency is greatly improved. There is not additional control circuit in the snubber. Simulation and experiment results confirm the validity of circuit, showing sinusoidal input currents and a ripple-less output voltage. The topology can be used as wireless base station power supply.